a. U₁₇ = 85

b. U₁₇ = 52

c. U₁₇ = -46

d. U₁₇ = -82

Penjelasan dengan langkah-langkah :

– Barisan aritmatika

a. 5, 10, 15, …

• Suku pertama (a) = 5
• Beda (b) = 10 - 5 = 5

Uₙ = a + (n - 1)b

U₁₇ = 5 + (17 - 1)5

U₁₇ = 5 + (16)5

U₁₇ = 5 + 80

U₁₇ = 85

b. 4, 7, 10, …

• Suku pertama (a) = 4
• Beda (b) = 7 - 4 = 3

Uₙ = a + (n - 1)b

U₁₇ = 4 + (17 - 1)3

U₁₇ = 4 + (16)3

U₁₇ = 4 + 48

U₁₇ = 52

c. 2, -1, -4, -7, …

• Suku pertama (a) = 2
• Beda = -1 - 2 = -3

Uₙ = a + (n - 1)b

U₁₇ = 2 + (17 - 1)(-3)

U₁₇ = 2 + (16)(-3)

U₁₇ = 2 - 48

U₁₇ = -46

d. -2, -7, -12, …

• Suku pertama (a) = -2
• Beda = -7 + 2 = -5

Uₙ = a + (n - 1)b

U₁₇ = -2 + (17 - 1)(-5)

U₁₇ = -2 + (16)(-5)

U₁₇ = -2 - 80

U₁₇ = -82